DMAIC

DMAIC (define, measure, analyse, improve, control) means the stages of process management. DMAIC is the key process of the Six Sigma approach to quality management and is used to give processes a stable nature according to the Six Sigma performance levels. DMAIC is used for the improvement of existing products, whereas for new products, DMADV is used and, for new processes, DMAEC.

Illustration of the DMAIC steps. Picture from wikipedia.org

It's mostly defined according to whom the customers are and what are their needs which the processes have to cater to, which is ciritical for the customers' expectations. It's in the measure stage that the current baselines are determined for improvement, which in the analyse stage much brainstorming usually follows in order to find out about the root cause of a problem or some common hindrance. The improve step sees the development of actual possibilities for improvement and the problems they are addressed to, while it's in the control stage in which the actual processes and thought-out improvement are implemented to sustain gains.

Chart summarising every step of the DMAIC cycle. source: http://ualberta.ca